Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D5564-95 – Standard Test Method Technical Guide
🧪 Scope and Significance of D5564-95
ASTM D5564-95 (Reapproved 2018) provides a standardized test method for determining the total ammonia content present in sulfonated or sulfated oils. Developed under the jurisdiction of ASTM Committee D31 on Leather, this method is specifically utilized by Subcommittee D31.08 on Fats and Oils for quality control in leather processing chemistry.
The analytical principle involves boiling an aqueous solution of the oil sample with an excess of alkali. The total ammonia is determined by measuring the loss in alkalinity after boiling through a subsequent titration step. All values stated in SI units are regarded as the standard.
⚠️ Safety Note: This standard does not address all safety concerns associated with its use. It is the responsibility of the user to establish appropriate safety, health, and environmental practices before handling reagents or samples.
⚙️ Apparatus Specifications and Reagent Preparation
The reliability of the method depends on precise apparatus dimensions and carefully standardized reagents. The table below outlines the critical specifications for the required glassware.
| 🟦 Component | 📏 Specification | 📐 Dimension |
|---|---|---|
| Erlenmeyer Flask | Material / Closure | Borosilicate glass / Glass stopper / 300 mL capacity |
| Air Condenser | Length / Outer Diameter | 915 mm (36 in) / 8 mm (5/16 in) |
| Condenser Connection | Lower End / Joint Type | Flared / Ground to fit flask mouth |
| Anti-Bumping Beads | Diameter / Material | 4 mm (5/32 in) / Chemically resistant, perforated glass |
Reagent solutions must be accurately prepared and standardized. Their strength must be expressed in terms of mg of KOH per mL to facilitate direct stoichiometric calculations.
| 🧪 Reagent | 📊 Concentration | ⚡ Equivalent Value (KOH) |
|---|---|---|
| Standard NaOH | 0.5 N | 28.05 mg / mL |
| Standard H₂SO₄ | 0.5 N | 28.05 mg / mL |
| Standard NaOH | 1 N | 56.1 mg / mL |
| Methyl Orange Indicator | 1 g/L | Endpoint detection (neutrality) |
💡 Pro Tip: Before use, perforated glass beads must be boiled thoroughly in several portions of water until the wash water reacts neutral to a methyl orange indicator to prevent any acid or base contamination.
📊 Analytical Procedure and Key Calculations
The procedure requires two distinct determinations: measurement of the total alkalinity of the sample and the loss in alkalinity after boiling with excess standard NaOH solution. A dilute sulfuric acid solution (1+19) is prepared for the titration, and solid sodium chloride and ethyl ether may be used during the sample preparation phase.
By calculating the difference between the initial alkalinity and the residual alkalinity after boiling, the analyst can accurately determine the total ammonia content in the sample. This method remains a cornerstone for analyzing leather treatment oils due to its precision and direct applicability to sulfonated and sulfated compounds.
❓ Frequently Asked Questions
🔍 What is the underlying principle of ASTM D5564?
The test measures total ammonia by boiling the sample with a known excess of alkali. The ammonia is driven off, and the remaining alkali is titrated. The loss in alkalinity is equivalent to the ammonia originally present in the oil.
💡 Why is the air condenser specified at exactly 915 mm (36 in)?
This specific length ensures sufficient reflux cooling to prevent the loss of volatile components (ammonia and water) during the extended boiling process, which is critical for obtaining an accurate titration result.
⚡ Which industries rely on this standard?
This test method is primarily used in the leather industry. It is directly under the jurisdiction of ASTM Committee D31 on Leather and is a key test for the fats and oils used in leather processing (Subcommittee D31.08).
📌 How is the solution strength expressed, and why?
Strength is expressed as mg of KOH per mL (e.g., 1 mL of 0.5 N H₂SO₄ = 28.05 mg KOH). This uniform expression simplifies the calculation of total ammonia by aligning with standard alkali equivalent weights used in the fats and oils industry.